METHOD FOR PRODUCTION OF POLYSULFIDE OLIGOMERS Russian patent published in 1997 - IPC

FIELD: synthesis of polysilfide oligomers being used as a base for sealing materials. SUBSTANCE: method involves production of polysulfide oligomers of organic di- and polythiosulfates, the process is carried out in aqueous medium at elevated temperature by using of hydrosulfide of alkaline metal. Organic di- and polythiosulfates having common formula R(S₂O₃Na)₂ and R′(S₂O₃Na)₃ where R is -CH₂CH₂OCH₂OCH₂CH₂-CH₂CH₂OCH₂CH₂- or and R′ is or are affected by interaction with hydrosulfide of alkaline metal, molar ratio of thiosulfates and hydrosulfide being from 1:1.5 to 1:1.9. The process takes place at 50-100 C, thus desired oligomers having common formula HS(RSS)_n,(R′SS)_mRSH with molecular weight 1000-8000 and n is 5-50, m is from 0.005/n to 0.05/n are prepared. Yield of desired product is 98-99 %. EFFECT: increased yield of desired product. 1 tbl